By:
Dr. Jeff Masters,
12:33 AM GMT on September 11, 2005
The latest 18Z (2pm EDT) runs of the GFDL and GFS models are in, and both continue the trend we've been seeing the past day or so of taking Ophelia more and more north. Both of these models are joining the NOGAPS model in taking Ophelia just over or offshore of Cape Hatteras, NC. It is becoming inreasingly likely that Ophelia will deliver at worst a glancing blow to the Outer Banks of North Carolina, and spare the U.S. a direct hit.
Before we get too enthusiastic about this development, we need to look at one more cycle of model runs. The 00Z (8pm EDT) runs of all the models will finish up sometime after midnight tonight. These model runs should have a much higher than average reliability. They will use data from the NOAA high-altitude jet, which is flying a high-density data mission tonight. If the models all show a continued track for Ophelia past the Outer Banks and out to sea, we can have some modest confidence that Ophelia will pull her punch.
Water vapor satellite imagery shows a substantial amount of dry air getting sucked into Ophelia on her west side, weakening her. The 7:30pm EDT hurricane hunters mission found a 1 mb increase in pressure, a gap in the south side of the eyewall, and reduced flight level winds of 73 knots. Ophelia may have lost hurricane status again.
The latest GFDL model continues to forecast that she will fight off this dry air and attain Category 2 status. The upper-level outflow is improving, but there is still 10 - 15 knots of shear from upper-level westerly winds. Category 2 status still seems like a reasonable forecast, but Category 3 is looking increasingly unlikely.
Dr. Jeff Masters